270 likes | 305 Views
Surfwood MWC CA2300590 County: Mendocino Jar Test. by Guy Schott 10/20/18. Source Water: Jack Peter’s Creek. UVT/UVA.
E N D
Surfwood MWCCA2300590County: MendocinoJar Test by Guy Schott 10/20/18
UVT/UVA • UV transmittance or UVT is a measurement of the amount of ultraviolet light (commonly at 254 nm due to its germicidal effect) that passes through a water sample compared to the amount of light that passes through a pure water sample. The measurement is expressed as a percentage, % UVT. • UVA – UV absorbance is calculated as a relative measure of the amount of light absorbed by a water sample compared with the amount of light absorbed by a pure water sample. • UVA = -log(%UVT/100)
Laboratory Charge Analyzer LCA: Used to determine coagulant demand of a source water entering the treatment plant. Source pH: 7.30 9800: 22 mg/L as product
Water temperature at 21oC 12 mg/L 9800 Filtrate 0.70 NTU UVT: 83.2% UVA: 0.080/cm 17 mg/L 9800 Filtrate 0.41 NTU UVT: 89.8% UVA: 0.047/cm 22 mg/L 9800 Filtrate 0.20 NTU UVT: 94.3% UVA: 0.025/cm 27 mg/L 9800 Filtrate 0.14 NTU UVT: 95.9% UVA: 0.018/cm
27 mg/L 9800 Filtrate 0.19 NTU UVT: 95.4% UVA: 0.020/cm 32 mg/L 9800 Filtrate 0.06 NTU UVT: 97.1% UVA: 0.013/cm 22 mg/L 9800 Filtrate 0.25 NTU UVT: 94% UVA: 0.027/cm 37 mg/L 9800 Filtrate 0.19 NTU UVT: 95.9% UVA: 0.018/cm
Water temperature at 21oC 17 mg/L 9800 2.55 mg/L 9890 Filtrate 0.45 NTU UVT: 90.5% UVA: 0.043/cm 22 mg/L 9800 3.3 mg/L 9890 Filtrate 0.07 NTU UVT: 96.6% UVA: 0.015/cm 27 mg/L 9800 4.05 mg/L 9890 Filtrate 0.04 NTU UVT: 97.2% UVA: 0.012/cm 0 mg/L 9800 8 mg/L 9890 Filtrate 0.9 NTU UVT: 78% UVA: 0.108/cm
1 mg/L 9800 7 mg/L Clarifloc Filtrate 0.13 NTU UVT: 95.9% UVA: 0.018/cm 2 mg/L 9800 10 mg/L Clarifloc Filtrate 0.23 NTU UVT: 88.3% UVA: 0.054/cm 15 mg/L 9800 15 mg/L 9890 Filtrate 0.23 NTU UVT: 95.6% UVA: 0.020/cm 32 mg/L 9800 4.8 mg/L 9890 Filtrate 0.19 NTU UVT: 96.1% UVA: 0.017/cm Water temperature at 21oC
Water temperature at 21oC 1 mg/L 9800 4 mg/L Clarifloc Filtrate 0.78 NTU UVT: 76.6% UVA: 0.116/cm 1 mg/L 9800 6 mg/L Clarifloc Filtrate 0.62 NTU UVT: - UVA: -/cm 1 mg/L 9800 3 mg/L Clarifloc Filtrate 0.9 NTU UVT: 73.4% UVA: 0.134/cm 1 mg/L 9800 5 mg/L Clarifloc Filtrate 1.0 NTU UVT: 77.7% UVA: 0.110/cm
Water temperature at 21oC 1 mg/L 9800 7 mg/L Clarifloc Filtrate 0.70 NTU UVT: 82% UVA: 0.086/cm 27 mg/L 9800 4.05 mg/L 9890 Filtrate 0.05 NTU UVT: 96.9% UVA: 0.014/cm 2 mg/L 9800 7 mg/L Clarifloc Filtrate 0.67 NTU UVT: 82.4% UVA: 0.084/cm 31 mg/L 9800 Filtrate 0.16 NTU UVT: 95.7% UVA: 0.019/cm
22 mg/L 9800 6 mg/L 9890 Filtrate 0.05 NTU UVT: 97.5% UVA: 0.011/cm 32 mg/L 9800 Filtrate 0.07 NTU UVT: 97.5% UVA: 0.011/cm 27 mg/L 9800 4.05 mg/L 9890 Filtrate 0.06 NTU UVT: 97.4% UVA: 0.011/cm Water temperature at 13oC
Jar Testing – Procedures • Fill jars with source water prior to coagulant injection and set paddle speed at 30 rpm • Add chemicals (i.e., NaOCl, primary coagulant, coagulant aid) to each jar • Flash mix for 1 minute (200 rpm for 1 liter jars; up to 300 rpm for 2 liter jars) • Slow mix for 5 minutes (30 rpm for 1 liter jars, up to 40 rpm for 2 liter jars) • Settled for 5 minutes • Syringe 25 mL from each jar taken ½-inch below surface (25 mL/12 sec rate) • Filtered through 1.2 um isopore membrane into cuvette (drip rate, 15 mL/90 sec) • Measure filtrate turbidity, chlorine residual and %UVT or UVA • Measure settled water turbidity after 25 minutes of total setting • Record all data
Jar TestFilterability Test Equipment Turbidity Instrument Syringe w/Luer-Lock Tip, 30 cc (part#: 2225800, by Hach) Swinnex Filter Holder, 25 mm (part#: SX0002500) Isopore Membrane Filter, 1.2 um, 25 mm (part #: RTTP02500) http://www.sigmaaldrich.com/
Jar Test - Filterability Test Syringe ~ 25 mL from jar (after 5 minutes of settling) Filter-to-waste 3-5 mL Filter directly into clean cuvette Measure turbidity Note: Take several readings before recording final NTU results. Micro bubbles can adhered to glass causing false NTU readings. To remove bubbles, tilt cuvette up to 90 degrees.
Contact • Guy Schott, P.E. • State Water Resources Control Board • Division of Drinking Water • Santa Rosa, CA For Stock Solution/Dosage calculations go to: • https://www.waterboards.ca.gov/drinking_water/programs/districts/mendocino_district.html • Guy.Schott@waterboards.ca.gov • 707-576-2732